You have 4 years. Not enough to start and complete a new rail project. So stock up on bollards and lane dividers. And start creating a physically separated bus lane on every major street right now.
They have been building a lot though, many lines are supposedeto open. If they are enough is an open question of course.
They could plan and build a few more lines in the next few years if they wanted, but it requires vision and such that we don't see in the us so they won't. it is still possible.
Yeah from what I read the biggest issue (besides not nearly enough lines, but like the first comment said can't build that much in 4 years, but hey let's try..), is frequency and dependability on the rail.
They need to prove that their rail system is frequent enough and has the capacity to carry olympic crowds. That's what I want to see, Metrolink and their subways running every 5-10 minutes, proving they can get people moving